1. What is the Capacitor Impedance Formula?

The capacitor impedance formula calculates the complex impedance of a capacitor in an AC circuit. It shows that a capacitor's impedance is inversely proportional to both frequency and capacitance, with a -90° phase shift represented by the imaginary unit -j.

2. How Does the Calculator Work?

The calculator uses the capacitor impedance formula:

Where:

• \( Z \) — Complex impedance (ohms, Ω)
• \( j \) — Imaginary unit (√-1)
• \( f \) — Frequency (hertz, Hz)
• \( C \) — Capacitance (farads, F)
• \( \pi \) — Pi (~3.14159)

Explanation: The formula shows that at higher frequencies or larger capacitances, the capacitor offers less opposition to current flow (lower impedance).

3. Importance of Impedance Calculation

Details: Calculating capacitor impedance is essential for designing filters, tuning circuits, analyzing AC circuit behavior, and ensuring proper signal transmission in electronic systems.

4. Using the Calculator

Tips: Enter frequency in Hz and capacitance in Farads. All values must be positive numbers. The calculator will compute the complex impedance with -j notation.

5. Frequently Asked Questions (FAQ)

Q1: Why is the impedance negative imaginary?
A: The -j indicates that in a capacitor, current leads voltage by 90° in phase.

Q2: What happens at DC (0 Hz)?
A: At DC, the impedance becomes theoretically infinite, which is why capacitors block DC current.

Q3: How does impedance relate to reactance?
A: The magnitude of the impedance (without the -j) is called capacitive reactance (Xc).

Q4: Can I use this for practical capacitors?
A: This is the ideal formula. Real capacitors also have equivalent series resistance (ESR) and inductance (ESL).

Q5: How do I combine multiple capacitors?
A: For series: sum the impedances. For parallel: use the reciprocal formula like resistors.